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Event: 846

Key Event Title

A descriptive phrase which defines a discrete biological change that can be measured. More help

Accumulation, Highly carboxylated porphyrins

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. More help
Accumulation, Highly carboxylated porphyrins
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Biological Context

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Level of Biological Organization

Organ term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help

Key Event Components

The KE, as defined by a set structured ontology terms consisting of a biological process, object, and action with each term originating from one of 14 biological ontologies (Ives, et al., 2017; Biological process describes dynamics of the underlying biological system (e.g., receptor signalling).Biological process describes dynamics of the underlying biological system (e.g., receptor signaling).  The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signaling by that receptor).  Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description.  To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons.  If a desired term does not exist, a new term request may be made via Term Requests.  Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Process Object Action
porphyrins increased

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE.Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
AHR activation-uroporphyria KeyEvent Allie Always (send email) Open for citation & comment WPHA/WNT Endorsed

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KE.In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
rat Rattus norvegicus High NCBI
mouse Mus musculus High NCBI
human Homo sapiens High NCBI
chicken Gallus gallus High NCBI
Japanese quail Coturnix japonica High NCBI
herring gull Larus argentatus High NCBI

Life Stages

An indication of the the relevant life stage(s) for this KE. More help
Life stage Evidence
Juvenile High
Adults High

Sex Applicability

An indication of the the relevant sex for this KE. More help
Term Evidence
Unspecific Moderate

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. More help

Under normal conditions, the heme biosynthesis pathway is tightly regulated and porphyrins (other than protoporphyrin) are only present in trace amounts[1]. However, when the regulatory process is disturbed, a variety of porphyrin precursors of heme accumulate in various organs including the liver and urinary and fecal excretion is elevated[2]). The pattern of porphyrin accumulation in chicken and rodents is similar following exposure to a variety of chemicals, and can be used to identify which enzyme in the heme pathway is predominately affected[1].

How It Is Measured or Detected

A description of the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements.These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA). Do not provide detailed protocols. More help

Methods that have been previously reviewed and approved by a recognized authority should be included in the Overview section above. All other methods, including those well established in the published literature, should be described here. Consider the following criteria when describing each method: 1. Is the assay fit for purpose? 2. Is the assay directly or indirectly (i.e. a surrogate) related to a key event relevant to the final adverse effect in question? 3. Is the assay repeatable? 4. Is the assay reproducible?

The hepatic and urinary/fecal porphyrin patters can be determined using a high-performance liquid chromatograph equipped with a fluorescence detector. Kennedy et al.[3] describe the method for tissue extraction and porphyrin quantification in detail, which is rapid and highly sensitive.

Domain of Applicability

A description of the scientific basis for the indicated domains of applicability and the WoE calls (if provided).  More help

Elevated porphyrins have been reported in mouse[4], rat[5], Japanese quail and chicken liver[6] and in clinical diagnosis of humans[2].  Elevated HCPs (highly carboxylated porphyrins) have been measured in Herring gulls from highly contaminated Great Lakes colonies[7].


List of the literature that was cited for this KE description. More help
  1. 1.0 1.1 Marks, G. S., Powles, J., Lyon, M., McCluskey, S., Sutherland, E., and Zelt, D. (1987). Patterns of porphyrin accumulation in response to xenobiotics. Parallels between results in chick embryo and rodents. Ann. N. Y. Acad. Sci. 514, 113-127.
  2. Frank, J., and Poblete-Gutierrez, P. (2010) Porphyria cutanea tarda--when skin meets liver. Best. Pract. Res. Clin Gastroenterol. 24(5), 735-745.
  3. Kennedy, S. W., Wigfield, D. C., and Fox, G. A. (1986). Tissue porphyrin pattern determination by high-speed high-performance liquid chromatography. Anal. Biochem. 157 (1), 1-7.
  4. Hahn, M. E., Gasiewicz, T. A., Linko, P., and Goldstein, J. A. (1988). The role of the Ah locus in hexachlorobenzene-induced porphyria. Studies in congenic C57BL/6J mice. Biochem. J. 254(1), 245-254.

  5. Goldstein, J. A., Linko, P., and Bergman, H. (1982). Induction of porphyria in the rat by chronic versus acute exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Biochem. Pharmacol. 31(8), 1607-1613.

  6. Miranda, C. L., Wang, J. L., Henderson, M. C., Carpenter, H. M., Nakaue, H. S., and Buhler, D. R. (1983). Studies on the porphyrinogenic action of 1,2,4-trichlorobenzene in birds. Toxicology 28(1-2), 83-92.

  7. Kennedy, S. W., and Fox, G. A. (1990). Highly carboxylated porphyrins as a biomarker of polyhalogenated aromatic hydrocarbon exposure in wildlife: Confirmation of their presence in Great Lakes herring gull chicks in the early 1970s and important methodological details. Chemosphere 21(3), 407-415.